I really like my rock rest from caldwell
http://www.exploreproducts.com/caldwell ... g-rest.htmBut it is out of your price range especially since you will also need a rear bag also.
but you coulld buy the rock jr
http://www.exploreproducts.com/caldwell ... g-rest.htmAnd a cheap rear bag for pretty close to your budget.
But a set of front and rear bags like Neuron posted has been working for countless shooters for a long time.
You can rig up your own if you have a few things.
I used to reload shotgun shells and used the cloth bags the shot came in(although thats not recommended anymore due to the lead content). Legs from a pair of kids jeans or sleeves from a denim jacket sewn up on the ends and filled with coarse sand or my favorite raw extruded plastic bits from an injection molding place.
I think you can get the stuff they put in bean bags and hacky sacks and such at craft stores. Or lentels or rice from the grocery store.
You can also buy corn cob media.
But using any kind of corn cob or food item like dried beans is inviting critter to chew holes in your bags if you leave them outside of some kind of container.
I lost my tackdriver bag to a mouse that must have had a feast on the corn cob media that I filled it with.