The crappy one can be 1* as well. the "good" one will be either 12T, 15T, 18T, 21T, or 24T. The 21T and 24T will supposedly be the fast trainers, with the 24T being worth the most and fastest.

You can get an 18yo 4* for $6M and 5-15T in the market, so this only saves you the cash, but costs a bit more token-wise. Its all up to you if you want to use the tokens. for 50T you can get a 6* scout with an SA.

Determine your needs and then evaluate which path you want to follow.