well I am bad at calculating the whole EV thing but I will tell you that at the NL50 there are a lot of weird players who will push with weird hands

he could possibly do it with a 2 pair or even be so far out of it that he thinks he just made a great slowplay of aces.

the question is would he slowplay a straight on the flop? perhaps - there is no flush draw

on the turn - if he is a real donk, there is now a flush draw and you made a bet in position after seeing lots of checks - could be semibluff and he wouldnt want you to see a cheap diamond

now - would he slowplay trips like this?
maybe he checked trying to induce bet to c/r on flop but when blank hits turn he would come out betting probably (or at least c/r)

the real question is did he hit a set of 8s? - very rarely!
only 2 possible hands could do that so I highly doubt it

personally - i would probably make the call and be convinced I had the best hand



P.S. bet bigger on turn - make it like 2, 2.5 - it'll still look like a steal