This article is from the Fencing FAQ, by Morgan Burke with numerous contributions by others.
Fencing shoes are available from many vendors and manufacturers,
including Adidas, Asics, PBT, Estoc, Sport-Escrime, Starfighter,
and various vendor house brands. Prices typically range from
US$50 to over US$200 per pair. Distribution of certain brands is
often geographically limited, and limited to fencing equipment
vendors in any case. In other words, don't bother checking at
the mall. The best mass-market substitutes for fencing shoes are
lightweight indoor court shoes, such as for squash, badminton,
racquetball, or volleyball.
Hard heel cups are widely used to absorb the impact of lunges.
They are integrated into some models of fencing shoe, but can be
purchased separately from specialty athletic and orthopedics
stores for other shoes. Softer rubber (eg. Sorbothane) inserts
are also commonly used to provide extra cushioning or prevent
chronic injuries from flaring.