This article is from the Recreational Figure Skating FAQ, by Karen Bryden with numerous contributions by others.
If rental skates are available the best path is to go with rentals for
at least a half-dozen sessions until you are reasonably sure that you
are making progress and intend to keep skating long enough to justify
the investment. The only contrary objection would be if the rental
skates at your rink are in really horrible shape, in which case you
may want to check if the shop or any rink/club bulletin board has used
skates for sale.