II was also ready to say the sales guy had a cbr600 sitting in the showroom and nothing like a gs500 to sell you
The OP established him/her self as a 17 yo 6’1 140 lb individual having ridden 125 and then 250 motocross since they were 14 yo, …yourself we know even less detail about, although you say sub 125 dirt bike is the biggest bike you have ridden.
So far the OP sounds just slightly more qualified than yourself to ‘ride’ any motorcycle.
Question is; if the three of us went dirt bike riding right now, would you be gimping along and crashing, or would you be blasting through corners, landing jumps, pulling cat-walks and exhibiting impressive rider skill ?
Problem is; you say you are on a budget.
If the answer is; you’re an athletic, skilled dirt rider with youthful coordination and reflexes, then I would even let you take my K100RS for a ride. Would the cbr600 make a good first street bike for either of you, possibly yes, if you have deep pockets and plan to ride it for the next 20 years, ( possibly even track race it !
If your answer is; you’re an average rider possessing average skills and presently looking for a street bike to learn on and ride safely on the street. The GS500 and SV650 are tons of bike.