OK ...
mybigventure.com - This domain is OK. I quite like it. You might get a sale on a domain forum or put it on Flippa. It has a certain amount of uniqueness and distinction to it. So, yes a sale is possible. It's going to be in the $ hundreds range.
playalldayelmo.com - If this is related to a children's toy Elmo, then this is likely to be a Trademark protected term and this domain is not suitable for resale.
affiliatesecrets2.com - I think you will be hard pushed to sell this one, but the 2 does add a bit of uniqueness and intrigue, so you might just get very lucky with a low value sale. Advertise it on forums.