I can't speak for dried mosquitoes but freeze dried blood worms over at Wal-Mart is relatively cheap. I paid exactly $3.46 for 8 grams of it. It lasts for a long time if you feed your flytraps once every two weeks.
This is the link to the freeze dried blood worms: https://www.walmart.com/ip/2-Pack-Tetra ... /493958276
I had to order online and had them ship it to the store for a free pickup since Wal-Mart employees at my area are slow as slugs when it comes to restocking product.
Let me also offer another alternative to feeding where 2 lb of it can last you for years, which is Maxsea 16-16-16. It's great for foliar feeding and wondrous results have been proven by before and after pictures by people here in this community. If you haven't heard of it, I suggest to do some research in order to get a better understanding for yourself of why you should consider it. Plus, it saves you on a lot of time from hand feeding CP's. Time is money!