Ok here we go, possible soapbox i dono well see how much into the weeds i get sorry in advance...
I have a 2014 P85D i currently have 116k miles on it. It has the original battery and original drive units. my 100% charge is 230 miles. I have gone in to the service center a few times, while i was under warranty i would go there for all kinds of random stuff like the seat squeaks against the center console. Now that my warranty is long past expired i only go there for things like parts or when i got the MCU2 upgrade. Tesla sells a lot of parts but sometimes they wont sell them if it is connected to a primary part, like the HV system or the steering.
For example like 6 months ago my charge port door sensor went out, whatever its an $80 part. I set up an appt and they want to change the charge port out along with the door sensor and i say no do a diag and when you realize it is only the door sensor i want to buy that part and DIY at home. Well it is a door sensor but its part of the HV system so they have to do the repair but they waived the diag fee because i was right but it was $120 in service fees on top of the $80 part that i could easily do at home safely.
Similar thing when i did the conversion to a heated wheel. I bought all the parts from a salvage tesla online and i admit it was my fault i broke the clockspring and needed a new one. You cant just buy a clockspring you have to buy the whole SCCM which was $250. Again i go down there and say i want this part and the say no its a restricted part and we have to install it. But they waive the service fee because they know its a stupid problem to have and are nice people at my SC at least.
But on another occasion my louvers went out, i was 80% sure it was the louvers so i had them do the diag and it was thankfully. I paid the diag fee and bought the louvers from them home and install in my driveway in a couple hours.
Also door handles yes they break but its not that big of a deal, its a minor inconvenience for a couple days till you get it fixed but not that bad. I have had 2 handles go out, both times it was the gear that broke and i have DIY the fix with the kit from EV tuning, which comes with a higher quality gear and better wires for the switches. Basically its a it breaks once and never again fix. I have 2 more kits at home ready to install whenever the other 2 handles go out but they are still factory parts.
So as you can see service is a interesting animal ya win some ya lose some.
As far as value for the car i bought mine used with 20k miles for $100k, about 1.5 years later a coworker buys the exact same car only its a may 15 and mine is a dec 14 car but other than that exact same car with 45k miles and he paid $47k for it. However, that seems to be the current point for the value, it has been sitting around $30-40k for my model for quite a while now. I haven't gotten into an accident (yet, knock on wood) but if i do the car is paid off and i have read a lot about diminished value claims and i also have free SC for the life of the car, and with the amount i drive that can add up to a good chunk of change as part of a diminished value as well. But i plan on keeping this car for as long as it still runs. I dont see the value dropping too much anytime soon. Also you mention the $30k range being your budget, why not save up for like a year or so and then you have a large down payment allowing you to take out a bigger loan. I saved for about 2 years and put $30k down on my car and paid it off in just shy of 3 years. Its all proper budgeting, not piss away money on crap you want vs need, (fast food, crap off amazon, exc.) Take public transit or ride a bicycle to save gas money/maintenance costs of your current car.
Thanks for coming to my ted talk.