Yes, this is a very important factor.

I am fortunate that I can both afford to buy some tokens as well as so far not being involved in bidding wars. Not sure if it is the lower lvl or my server but there is really nobody competing for the fast training nordgens so I get them for 1T and their starting bid.

I then try them out to see if they play well, keep those that stick and sell those who don't. Rinse and repeat basically. I now have 10 of the 11 positions locked down, I thought I had all 11 but my 19 yr old RB just fell apart in his 2nd season out of nowhere in spite of being trained back to 7* like the rest (I have one ST who I got to 8*). Everyone else is pretty consistent. My CK specialist did see a drastic drop in assists which I cannot figure out but it hasn't hurt my stats as a whole so meh.

But even if you are on a strict budget you can win in other ways. You just buy cheaper veteran players who are close to 6*. You have to rebuild a lot that way but you can have success. Just have to be more careful in bidding because in my experience there is a lot more competition for the cheaper players.