So my tent is 84in long and 47 inches wide, do you think two of the 8ftx10ft tarps linked below would do the trick even though they are bigger than the base of my tent?

http://www.amazon.com/Stansport-T-810-Reinforced-Multi-Purpose-Tarp/dp/B003WH7N7Q/ref=sr_1_3?s=sporting-goods&ie=UTF8&qid=1464620823&sr=1-3&keywords=camping+tarp

https://www.amazon.com/dp/B07P1NWGL4/ref=cm_sw_r_cp_apap_uj2rCMtPDPg9i

This is my new hammock this season and it's been great. I have heard the suspension is stretchy butnstill functional, I swapped mine for cinch buckles and ratchet straps which you could also do in your budget.

Edit: looks like this isn't available anymore. There are other hammocks of similar design out there, try to find something 11 foot long.

https://www.amazon.com/dp/B003WH7N7Q/ref=cm_sw_r_cp_apa_i_srJ-EbKXJ0DJ9

I used a tarp like this my first year and it's more than adequate. Additionally if you do upgrade your tarp at some point a good simple heavy duty tarp is always useful.