No, LASR Classic and LASR X are seperate products.
"Is there an upgrade price?"
No. LASR X is a seperate product, not an upgrade.
"Can I exchange LASR Classic for LASR X?"
If you within the 30 day return/exchange period, then yes. Otherwise, no.
"So I have to purchase LASR X if I want to use it?"
Yes. It is a seperate product.
LASR Classic, as a product, is not going anywhere. It is continuing to be supported and, in fact, continues to out-sell LASR X. LASR Classic will continue to trump LASR X in several areas, including offline usage, features and functionality, advanced compatibility and customization, and use with the LASR Advanced Camera. LASR Classic was always clearly advertised and marked as Windows only software, and the now obsolete "Mac Version?" FAQ topic clearly stated that there was never any plans to make a Mac version of LASR Classic.
LASR X is a separate product from LASR Classic for a variety of reasons, and there is no specific "upgrade" as one product is not necessarily better than the other one for the already stated reasons. In fact, going from LASR Classic to LASR X would be a downgrade in most ways. The two share no common code, and LASR X has been a considerable investment of time and money to create, and we still have a ways to go in order to add all of the features and functionality into LASR X that we are planning for.
If you would like to use LASR X, you can give it a try for as little as $9.