If you're not making a lot of power that might be OK. Click that link to see what's available. Chains is one place not to cheap out. Broken chains lead to broken cases. Economy sprockets just wear quicker.
I've not heard of Volar, but the ad seems to include legit stuff ?
I've pretty much tried all the cheap chain/sprocket sets ebay has available and found myself constantly adjusting the chain during a season and replacing each spring. the cheap colored chains would have cost me a set of cases if I didn't run a case saver from Ken Oconnor Racing. the first one made it a week, the second one made it 1/2 mile. both were on decent shape but used sprockets.
then I decided to spend the extra 20 sum bucks and get a $70-ish setup.... JT sprockets and Primary Drive non o-ring chain from ebay. the last I rode regularly I adjusted it a little only twice that season.
similar to these .....
spend the few extra $ and save constant adjustments, premature wear and possibly broken cases, and always replace them as a set ... chain and sprockets together !
JT, Primary Drive, RK, DID, Renthal to name a few, all make reputable stuff.
Volar ?