do a google search for "horse racing exotics house edge". Multiply that by 1 and that's your expected loss to earn $200 in 'wagering credits'. Skim through the rules to figure out the value of those credits; which will be somewhere between $100 and $200, depending on what bets you can use them on; or just assume the lower amount if you can't trust your own reading comprehension. Subtract the expected loss from the value of the wagering credits, and that's how much this promotion is worth to those of us who know nothing about horses.
A better question is how you've been doing this for 30 years and still don't know how to figure this shit out.