How much would it cost me to build a fast car?

I had a question… My mom has this really old 1995 Ford Taurus she's thinking about selling it this car is really beat up from the inside no dents from the outside though the engine is pretty bad but it still runs its been her daily driver for about 5-6years she wants to sell for 300$ but I wouldn't want her to let it go for that much and I was wondering how much it would cost me to basically make this a fast little son ***** pull the back seats out and everything
I wanted some recommendations on what engines and transmissions were good to fit this car v8 preferably with a budget of around 3-5k

Ford Taurus or Infiniti I35 as first car?

Okay, this is an odd question, and I know you can't really compare these cars, but I'll explain. As my first car, my grandma is offering to sell me her 1999 Ford Taurus. The problem is that, even though it has low mileage (she doesn't drive much, so it only has about 85,000 miles on it) she said the transmission could be going out because it doesn't drive as well as it used to and I think she said sometimes it will start randomly accelerating. While I wouldn't mind driving her car, the Kelley Blue Book value for it is only about $2,700 and I already know that rebuilding or replacing a transmission is going to cost more than that. I'm also unsure because by the time I get my license the car will be 17 years old. However, I know that she has maintained the car well.
On the other hand, the Infiniti I35 I'm considering buying is a 2003. I know it's four years newer and it's a luxury car so it can't really be compared with my grandma's Ford but it only has around 110,000 miles on it. While it's being sold at a dealer in my area, not by a family member, me and my parents have seen the CarFax for the vehicle and it too has been maintained well. I know the Infiniti would be more reliable. However, my parents say it's overpriced (the dealer wants $5,500 for it) but I know its resale value would be much better than that of the Taurus and it would have more features. If it was your decision, which one would you buy?

Why won't my ford taurus start?

Going 65 down a highway then pedal to the metal the speedometer gets lower and lower until about 30 then just dies altogether… Sat on side of road trying to start it for about half an hour then it starts and goes about a mile and the exact same thing happens… Now it will not start.is it fuel pump and how can I tell

Why does my ford taurus stay in first gear too long?

2000 Ford Taurus ses when I start it up the doors don't lock, the speedometer doesn't work and it stays in first gear for a while and then seemingly randomly( hot cold running a long time or just started) it'll eventually kick into the next gear the doors will lock and the speedometer will work but sometimes it takes a really long time

Why didn't anyone take care of this car?

I'm 17 and I'm looking at cars. I'm looking at all sorts of different cars. I was looking at the 2000-07 Ford Taurus. I noticed these cars sell for good deals with very low mileage. I've driven one and I didn't think it was a bad car at all. I noticed a lot of them I find online are quite beat up and barely have 150,000 miles on them. When I find a Mercury Sable, it looks like it was taken good care of. Why didn't people take care of this car?