Cheaper separately? cant you use a flat rate cardboard envelope? Then it costs $5.00 to any where in the USA! heres a link its a large envelope! I use them all the time. https://shop.usps.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10052&productId=10000242&langId=-1&parent_category_rn=10000002&top_category=10000002&categoryId=10000036&top=¤tPage=1&sort=&viewAll=N&rn=CategoriesDisplay&WT.ac=10000242
Sorry that link didnt work heres a better one https://shop.usps.com/wcsstore/ExtendedSitesCatalogAssetStore/upload/images/ep14f_f.jpg There at the post office or you can order a stack of them free delivered to your home! https://www.usps.com/
WOW ups doesn't like you copying there photos let try this one LOL https://shop.usps.com/wcsstore/ExtendedSitesCatalogAssetStore/upload/images/ep14f_d.jpg
nope i give up but there at the https://www.usps.com/ web site just look for the free shipping supplies there the 14 by 10 envelopes. No mater what you put in them or how heavy they are its just $4.95 to send them!