since Heavycoin uses the HEFTY1 algorithm this will increase difficulty really high and with it the price.
The price will only go up if there is demand to buy it. If you look at DOGE, for example, the return has halved twice, on 14th Feb and 17th March. If an increase in the cost of mining automatically resulted in a price increase, the price of DOGE would have increased after these two dates, but in fact it has been going steadily downwards since mid Feb:
https://www.cryptocoincharts.info/v2/pair/doge/btc/coinedup/3-monthshttp://en.wikipedia.org/wiki/Dogecoin#Block_scheduleI'd say it's by no means certain that a flood of GPU miners onto HVC will increase the price.