For those of you that are looking for reasonably priced graph paper, I discovered this source. It is a little lighter weight than some, but very reasonable at $10.01 for 500 sheets, including the shipping! Unlike some paper I found, it is printed on both sides and will stand up to erasing. They also sell packages of padded sheets with 12 pads of 50 sheets each. They offer many different grid sizes.
https://www.ebay.com/itm/School-Smar...0/174625960434