Lowes offers Miracle-Gro Mini 2.4-ft L x 4.7-ft W x 6.3-ft H Clear Greenhouse Kit for $59 (reg. $89) with free shipping. 

Product Description:
Start seedlings early or extend your growing season late with the Miracle-Gro Mini Greenhouse This easy-to-assemble, compact greenhouse is constructed with a high-grade tubular steel frame. The clear PVC cover allows the maximum amount of light to reach the plants, even in cooler months. The cover protects young seedlings in the early Spring and Late Fall weather.

• The frame is made of 5/8 inch high-grade tubular steel
• The frame has a powder coated finish that resists chipping, peeling, rust, and corrosion
• The Miracle-Gro Mini Greenhouse has a fitted clear PVC cover with integrated tie-downs
• The cover allows the maximum amount of light to reach the plants
• The cover has a double-zipper door for easy access to plants and seeds
• The four sturdy wire mesh shelves can be removed to accommodate taller plants and accessories
• The Miracle-Gro Mini Greenhouse can be assembled in about 15 minutes with quick-snap assembly and no tools required