A deep discount wheelchair online store is NOT for everyone. If you are looking for more traditional retailers to find wheelchair parts, here are some options.
These retailers are likely able to ship wheels to you faster than DIY Wheelchair Supply since they don't use vendor drop shipping from China.
NOTE: This is not a recommendation. It is a reference listing.
Distributors
DIYMobilityParts.com
DME HubWheelchair Parts.net
WheelchairBearings.com
SportAid
Wheelchair Parts.com
1800Wheelchair.com
Southwest Medical.com
Spinlife.com
RollinginParadise
HowIRollSports
Manufacturers
Froglegs
Spinergy
KiMobility