I have a set of both, and while I was completing them I noticed very little difference in price. I remember I needed the same issue # for both the bar code and spidey versions and the dealer I bought them from had the exact same price for each.
When I was a kid I collected the bar code versions because the only place to get comics in my small home town was the newsstand. So those have some sentimental value to me. I would guess the desirability of one version over the other is mainly a personal preference.
Premium used to be on direct copies (bought at comic shop, Spidey instead of bar code), but that seems to no longer be the case. There are some instances with other titles, not sure about Star Wars, where one has more printings than the other.
Thank you echostation and comicalUser. I've got a mixed set that I put together in the early 90's. Shoulda paid more attention. I went for just # and condition. Is a mixed collection considered complete # wise or should the covers match?