Need Bitcoin Buying assistance/advice, Please help.

Here is the situation:

I need $2000-$3000 worth of BTC every week. I sell this BTC for a profit. My issue is I am very BEARISH toward bitcoin prices currently so thus I don't hold bitcoin long and don't believe in paying more than coinbase +1% which is what I can pay coinbase anytime.

Here is my problem:

I don't want to use coinbase because when I acquire BTC I simply sell it to exchanges and then convert back when I have someone buying from me. The problem with coinbase is over the course of 5 days the exchange price can and has dropped 10% or more killing my profits and thus putting me in the red for the week overall even after sales. I'd rather take the risk of market movement out of the whole process for 5 days waiting period.

I make about 10% margins on my trades and do not want to lower that, 10% is the lowest I will go for the amount of time I spend with it all. I feel like the amount I move is too small to send to an exchange. If I send to an exchange I'm looking at huge wire fees.

I'm really stuck on what I should do or how I can continue to buy BTC at market rate. I know coinbase in the past when they reach their max buy limit for the day, they would let people buy but base the exchange rate on whatever the rate is come 5 days from the purchase being initiated. This is what I would prefer honestly.

Any advice here would greatly be appreciated as I am stuck and as the exchange rate continues to fall, less and less of my weekly vendors are willing to sell for market price. I wish this damn currency would just be stable.