Turtles are actually pretty high maintenance, they require expensive tanks and all will grow to the size of a dinner plate.
You may seem them advertised as minature, etc. but there is no such thing as penny turtles. On top of that they require lighting and special diets. They're a pretty hefty commitment, its not unusual for them to live 70 years or more.
And they aren't easy to rehome when they aren't little and cute anymore.
I thought that it would be fun to look at different pets that don't get a lot of attention these days.
You have a few main options that are low maintenance but still nice pets. Low Maintenance doesn't mean low cost tho.
Cheapest, low cost option would be get a 5 gallon tank, heater, some timed lights, and get a beta, with a snail or two. You will need to cycle the tank (look up the nitrogen cycle, and a lot of you tube vids and guides on how to do this, but the basic of it put some fish flakes in an tank with out fish and let it sit for 2 weeks) Then keep the water around 70ish, and then you only need to clean the tank once every week (taking about 30% of the water out and replacing it and adding a dechlorinator, and quick wipe down of the tank walls), and feed daily. The snails will help keep the tank algae free.
Cost about a $100 bucks to set up.
These are fun to look at but not much else.
You'll spend about $5 bucks a month (food cost as well as supplies)
More costly then a fish, as well as still a pet you watch not play with, they cost anywhere from $15 on up. I would suggest a Rose hair or a Golden Knee as a starter. You will need to set em up with a terrarium , heater , and keep it semi moist, as well as you will have to feed em crickets or grubs so if live insets creep you out stay away. Clean cage weekly, feed them 1 or 2 times a week.
Cost to set up : $200 ish for a good set up don't want to go cheap and the terrarium and have them escape on you.
While you can handle them its not advised to do it. They are to observe for the most part. Some can get rather mean when held as well and can very fragile, a fall of lest then a foot can be fatal for them.
You will spend about $10 bucks a month give or take for crickets might be cheaper where you live or if you decide to buy in bulk, but my local pet smart has a 20 pack for $2.50 for sale that perfect for a weeks worth of food.
Frogs, and other amphibians
Stay away they might seem cheap but very hard to keep alive with out keeping the right water and environment for them.
Rats, and other rodents (hamster, and such)*
You said you didn't want a Rat in your post. I would agree to, they are not very low upkeep as they are social pets, if you don't plan on playing with them daily they will grow sad and depressed. As well as you have to get more then 1 for them to thrive. Other then Rats, most other rodents are just for watch not play as well as they get stressed easy.
I would honest go for the Beta fish.
What's particularly interesting about pet healthcare is, besides the usual insanity of many pet owners, is what it says about human healthcare.
Pet healthcare is in a wolrd were vets require next to zero malpractice insurance, the FDA regulates all animal drugs and procedures far less than humans, pets live short lives compared to humans so any benefits are easy to observe and research, insurance and HMOs and government programs are barely involved as most buyers pay cash, veterinarians themselves are generally in oversupply, etc. It's as close to an ideal perfectly competitive free market of healthcare as we'll ever see.
And what's the result in America?
The reason I say that sentence might be a clue is that I think there has been a real and substantial cultural shift in the US in regards to how we treat our pets. The fact that I spent as much money as we did to even get to the point of an inconclusive sonogram is much further than my parents would have gone with a pet and way, way, way, way further than my grandparents. I think as a culture we are more willing to extend some level of person-hood (for lack of a better word) to our pets than we used to be.
And part of that is spending more on veterinary care. I think it might be that people are more willing to spend money on diagnostics because they see their pets more as part of the family and less as a special case of farm animal.
A generation or two ago I suspect people were a lot quicker to opt for euthanasia at the first hint of illness.
I personally don't know anyone with pet insurance.
My parents, as an example, had many pets and they've never had insurance. They've just found that for them personally, they'd pay more in insurance than they'd pay out of pocket for the yearly check-ups and everyone needs.
I thought it would be worth it in case of any medical emergencies and so I got a plan. They requested prior vet records, which makes sense. I had adopted a cat from a shelter, and while in the shelter she had developed a rash and had caught a stomach bug. Neither of which were permanent and both of which had been treated and fully cleared up before we got her. They said this was fine, not to worry, obviously it was no big deal because they weren't long-term or recurring illnesses and were situational. I fully signed up and had a monthly payment.
Month four of my payments, I notice it's a lot higher I call and ask what's going on and the agent on the phone tells me they can't disclose any information so they'll be issuing me a letter...uh, okay? I get the letter a few days later and it states that after a re-assessment of my cat's prior vet records, they have decided she is a high risk and they will continue to "insure" me and take my money, but they will not be covering any medication or treatment that deal with her "skin or internal organs."
So basically they would cover dental and vision, and nothing else. Awesome. I cancelled my plan right there.
I think before deciding on insurance you should figure out how much you can expect to spend yearly on your vet bills. Obviously neutering is a big overhead cost, but outside of that.
How much will flea/tick/heartworm prevention cost per year?
How much will the yearly shots cost you? Will it be worth paying the $700 or will it be under that? Of course, also take into consideration that if your pet needed an emergency surgery, would you be able to cover it out of pocket?