They are both grammatically correct and essentially mean the same thing. However there is a very subtle difference. Now means this very second, time being could last for a few days. to utitlise the phrasal verb in the second sentence you could say instead. The price is low for the time being, but it could change. You don't need to say tomorrow. Because the phrase time being in itself suggests that it could change in a few days. To be perfectly clear on the message ie the most important part of the message is that the price could change tomorrow I'd use the first one. If the more important message is that the price will stay low for a while, then use the second one. Ultimately the difference is so subtle that most people wouldn't really even notice.

Hi, there is absolutely no difference in meaning between these two sentences. Both are good.