As it is considered a lucky number, banknotes with a serial number containing 777 tend to be valued by collectors and numismatists. The US Mint and the Bureau of Engraving and Printing sells uncirculated 777 $1 bills for this reason.
If you ask your guides for a sign, then 777 is a good indicator that you are on the correct path. To open up to receiving both love and twin flame love, you need to let go of negativity. The angel number 777 will let you know when you have reached that open state that will allow love to come to you.