One of my biggest pet peeves is when I am on a location shoot and can not find the lens cap after i'm done shooting. I've lost them countless number of times in various locations, but can never seem to find them again. One of the best parts abou Ebay is that you can find direct low cost alternatives to many things. Lens caps can be affordable if you know where to look. I've ordered 10 lens caps to keep at the studio at all times just so I have a lens cap when and where I need it. Here are some readily available lens caps for cheap:

BLUE ENGINE OIL CAP ECLIPSE LANCER EVO GALANT 3000GT    US $19.99

Pentax-K SMC 17mm f/4 Fish-Eye lens Film or Digital    US $395.00

WIDE ANGLE 0.5X LENS 30mm FOR Samsung SC-MX20    US $24.95

One Rim- 20 x10 rims fit 2005 2008 Mustang ® V6    US $193.75

CANON 18-55mm IS LENS+58MM UV/CPL/FLD FILTER~DELUXE KIT    US $129.95

*NEW* D90 Digital SLR + 3 Lens: Nikon 18-105mm VR L@@K!    US $1,299.99

Burris AR-Tripler 3x Magnifer Matte 30212 Model# 300212    US $199.99

Camera Lens Cap Cover Holder For Digital & Film Cameras    US $2.88

17 x 9-10.5" Gunmetal Fits Mustang ® Cobra wheels DEEP    US $537.00

Tamron 70-300mm Di Lens for Sony A900 A100 A350 NEW    US $157.95

Nikon Digital SLR Accessory Kit +Lens+Bag for D200 D300    US $249.95

Professional Lens Cleaning 4tools kit Camera Telescope    US $12.13

62mm MACRO CLOSE UP Lens 4 Filter Kit Set +1+2+4+10 NEW    US $25.95

Magnalight EXP-LED-HL-1W Explosion Proof Headlight -    US $99.00

CANON EOS Rebel XS 1000D D-SLR CAMERA+ ~* 3 LENS KIT *~    US $539.95

NEW! KODAK Zi6 ~PK~ HD DIGITAL CAMERA CAMCORDER +2GB SD    US $104.95

18 x10 Chrome GT40 wheels rims fit 1999 2000 Mustang ®    US $695.00

CANON EF-S 18-55MM~ IS~18-55 MM f/3.5-5.6 SLR LENS    US $109.95

Super 16 Movie Camera Krasnogorsk-3 16mm *MINT* *NR*    US $350.00

NEW NIKON AF-S 18-105mm ED VR ZOOM LENS D3000 D5000 D90    US $299.99