Under 100k miles, well, that doesn't really matter since I'd be doing a GTE swap. But should it be under 10k?

depends on the actual millage, clean tittle what not. conditon of the body. why do a GTE swap why not just go ahead n buy a dawg with the 2JZ-GTE?
well to answer your question i highly doubt u will get one that is under 10k. i seen alot of N/a go from 13-15 some even in the 20's

Well, to be honest. I didn't want to get a 2JZ-GTE right off the bat because I'm paying for my insurance and car (I'm 16.) Later on, when I did get some money, then I'd be able to afford a GTE, but I figured, "Why buy a whole new car when you can buy a shortblock for $2700?" Find a Getrag 6, a new ECU, and a turbo...and I'm set...right?

I was once your age and I hate to say it but your wrong. Your trying to go about it all wrong. Do not and I repeat do not buy a NA to swap to a TT unless your getting the car as a project and completely gutted. First there is way to much to do in the swap and its alot more work then it seems. Second you said something about shortblocks. Did you not read the description, it isnt a whole engine and no you can not bolt it to the NA motor. A shortblock is useless without an actual GTE motor so you pay 2700 and then you still need to get a whole jdm motor which is 3grand or maybe usdm which will cost you about 5grand. Second you seem to be just throwing the 6spd out there, not realizing that it is nearly impossible, at this time, to find someone selling and that will cost you about 3 grand if your lucky. To buy a new one cost about 5grand from titan motorsports. Also you didnt do much research because to go from NA to TT you will need a new driveshaft, differential, axles, and alot of other little things. Now a differential can cost I believe 3 grand from elmhurst toyota. Basically unless you plan on having the car sit for about 5 years while you gather up parts that are used (and thats being kind) then your going to spend a bundle. I was also mislead to think that an NA is easily swapped but it doesnt work like that unless you know alot of people or get very very very lucky. I see your from texas so you should talk to PowerHouseRacing, they do the swap but it will cost 11grand but they will do it all for you. I suggest if you do actaully plan on doing a NA to TT swap you do a SHIT LOAD of research dont think its just plug and play. There is a boat load of information on this stuff but in no way should you ever consider it a simple swap like it sounds like you are (Im talking about the way you worded your response). Also do not start with a automatic, start with a 5spd if you do, it doesnt cost as much to find a 5spd then trying to install pedal assembly and modifying the subtunnel to fit the 6spd tranny.

Now as far as an NA going for UNDER 10k. You are very mistaken there. Unless the car is an absolute piece of crap. People consider my deal to be a good one when I bought my white 97 NA for 15k. If you are just going to rip the car apart dont buy a 97 or 98. Buy a old model like a 93-95 or something. a 97 and 98 can go up to the 20's and above and you could find a 93 for probably 13k if you look hard but your going to get a very beat up body. You have to realize that even the NA is a amazing car and very rare and people are trying to get them just like a TT. Im not trying to be an ass, just trying to inform you before you go ahead with something stupid. People dont take enough time to research this stuff. Ok I could go on forever about this but I think I summed it up enough. Believe me I have spend way to much time on this topic and after exhausting all possible alternatives I decided to just go TT from the start.