Well, I can think of a few ways of including price in a MaxDiff.
Of course you could include a price for each of the 8 concepts - this would tell you how much the 8 combinations of concept and price are preferred by respondents, and if you add a direct anchor question, you could see that relative to a cutoff in terms of propensity to buy.
Alternatively you could do a variant of the options pricing model. You might make 3 versions of each concept, so that each concept appears with a high, medium and a low price. Make sure in the design to prohibit the same item from appearing with two different prices in the same question. Now when you run your MaxDiff, you can see a price curve for each of the 8 products. And if you add a direct anchoring question, you can also have a measure of absolute, instead of just relative, threshold for buying.
Of course all of this assumes that you want price in at all. If you just want the relative value of the 8 concepts, and you don't care about priced, then leave it out.