To answer both questions: extremely expensive to make good ones (billions?) and no, they are not currently a good alternative. Theoretically, they would be amazing due to the constant blood shortage, but alas…
My understanding is that they have been invented, made and administered (several varieties, apparently) but that haven’t been particularly safe. From what I could gather from reading some review articles on pubmed (here’s an example: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2728196/) artificial blood products have been developed but are associated with greater adverse reactions (especially cardiovascular) and have not been proven to decrease mortality (which would be the point). Further research seems to be occurring on the topic (http://www.ncbi.nlm.nih.gov/pubmed/20392662) but I didn’t find any “breakthroughs” per se.
However, I am not a scientist so my understanding of the second article especially is somewhat limited. I’m not sure what prompted your interest, but it’s an interesting question!