So my first match, I borrowed someones gun who had it all setup and doped and all. I shot a 58/60 so instantly was hooked. Havent done that well again lol. Ive shot a fair amount of FT last year as it quickly became my favorite shooting discipline. There are so many combos and setups you can do and none are right or wrong. Glass does make a difference and the guys using Sightrons and Nightforce claim they have perfect ranging. I had no issues with my Argos BTR 6-24 Gen2, until it got darker in the woods, then I struggled but so did they. I had bought a Marauder with LW barrel in .177 as recommendation from people here, never shot it in a match, After I borrowed a gun, I went and bought my own, an AirArms S510XS. Amazing gun. The Marauder i just as accurate I believe as the s510 but I prefer the s510 over it for looks, fit and finish. The marauder is now a backup or to lend out to someone. It absolutely can be done for less money and still be semi successful but I will say, confidence is huge in this game. Having good equipment that you can count on and are confident in the longer shots will make all the difference. Good equipment will help with that ranging at 51yards in a dark shaded lane where one scope reads 42yards and others read the actual 51yds. Ranging is everything here along with an acceptable accuracy. An avenger in 177 should get the job done but unless your holding 1/2" at 50yds (1MOA), your going to have more misses just based on the inherit accuracy of the gun, let alone all the other factors involved.
I love HFT and wish I could shoot it locally weekly.
Get a 177 and id recommend going with a larger objective and tube scope for more light. Get something you can fine tune the fps so you can shoot 10.5gr and try the 13.4gr (I cant adjust my finely so I cant shoot the 13.4gr, puts me over 20fpe). The Gen2 Athlon Argos is a decent scope and would suffice for most your needs. The gun is up to you but whatever you get, id want the most accuracy at 50yds you can get for your money. (research this heavily as $$ buys accuracy to a point). Buy some good quality named pellets and go shoot. My setup would be a Marauder with LW barrel,Huma regulator, Argos BTR 6-24 scope, JD Customs wheel, and Benjamin Match 10.5gr pellets. You should be able to get that for your budget if your willing to buy used. $300 for the scope, $500 for the gun or less,$100 for the Huma reg, and $100 for the wheel and $100 for pellets. Report back.