I would plan for the worst. In either case, the tops are NOT strong enough to support the weight of the car.. thus, they can either fly off, or crush down onto you. IIRC, there are only 3-4 mounting points for the hardtop.
BK, could be a better alternative. Used, I paid about $350. New, about $700. Then again.. And believe me, there seems to be an active market for "previously owned" BK bars because of the Price issue you mention. Think about it though.. it is only your head and neck you are looking to protect. How much does a new head or neck run these days?
people, myself included, have a very personal take on what is safe and what is not. And people seem to love to spend huge amounts of money on "go fast" items, tires, extra rims, etc.. why not spend $2-3k on safety - helmet, gloves, shoes, Head and Neck restraint, seats, harnesses etc. That money will be good for "3-5" years. Tires? Spend $1200 and good for maybe 1 season.
Just some free banter..
As Bell helmets had in their ads many years ago :
" If you have a $10 head, get a $10 helmet

"