the two levels you are talking about OP are COMPLETELY different... 2/5 is a 3x+ buy in of a 1/3 table.
if you are playing 1/3... you are going to need somewhere around 10k to play very comfortably. you can probably get by with 5k-7.5k(7.5 is 25x)
2/5 is another ball game. you should have about 25k to play well... though you can probably get by with 20k.
anyway you look at it you should have about 25x to play correctly. and that is on the very thin side of things, as some suggest 30-50 BI's.
Schubackfrombeingbannedfortalkingaboutproxys