Anybody using wig wags for trailer lights ?

Anybody using wig wags for trailer or their TV lights ?
Some cost $20, some $40 some $50 ????
What's the difference ?
http://www.amazon.com/gp/product/B001E3WDN4/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1
http://www.amazon.com/gp/product/B0036RFLR6/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1
http://www.amazon.com/Knight-Riderz-Sequential-Light-Flashing/dp/B002U2D8JG/ref=pd_sim_sbs_auto_3?ie=UTF8&refRID=07R2VE8SHY77V97SZ284
Some cost $20, some $40 some $50 ????
What's the difference ?
http://www.amazon.com/gp/product/B001E3WDN4/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1
http://www.amazon.com/gp/product/B0036RFLR6/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1
http://www.amazon.com/Knight-Riderz-Sequential-Light-Flashing/dp/B002U2D8JG/ref=pd_sim_sbs_auto_3?ie=UTF8&refRID=07R2VE8SHY77V97SZ284