Cross breeding might reference an albino and a standard, but they are the same species, it just means that a standard color will likely have a recessive gene so their babies will include a few albinos. There is nothing wrong with that, and it certainly does not negatively impact their health or lifespan. He might be confused and think you are line breeding, which can cause problems if it's not done properly (meaning, culling unhealthy/deformed individuals). Line breeding means breeding within the same family line--ie, father breeds with daughter, and this is done to reinforce a specific trait, such as long flowing fins or a interesting color. To be done safely, culling must be used, and occasionally introduce an outside breeder to provide adequate genetic variety and avoid too many nasty recessives. With fish, line breeding can continue for a LONG time with minimal impact, particularly if culled regularly.
Price is dependent on the market. You might look for a local fish club auction--that's how I got all of mine. I picked up 10 for about $15 that were all less than 1 inch and unsexed (I really don't recall what I paid, $15 is the max I planned to spend so we'll say that's what I paid). For the pair of reds, they were closer to 2 inches and sexed as a pair, think I paid $12.
With that many fish, the big thing will be a) water quality, b) aggression, and c) hormones. Do lots of water changes, even if the nitrogen tests are low, since there will be a lot of things building up that you can't test. So long as everyone is eating and healthy, it's fine for the short term.
