If you want a really cheap lens that will cover 4X5, you can sometimes find an old 3A folder with a triplet or tessar type lens for less than $50. These cameras are 3-1/4 X 5-1/2 format, and their lenses will cover 4X5. When I bought an off-brand 4X5 camera last year, the first lens that went on it was the f7.5 triplet off my Ansco 3A folder. I think the focal length is around 170mm, and it would be sharp enough for 11X14 or 16X20 enlargements except the very corners would be just a bit soft, but not bad.
Some of these cameras, however, had meniscus or RR lenses that wouldn't take much, if any enlargement.