Alaska Mileage Plan and Rocketmiles offer up to 4,000 bonus miles to Alaska elite members using this link https://www.rocketmiles.com/mvp-bonus.
The offer for non-elite Alaska Mileage Plan members is just 3,000 miles and available at https://www.rocketmiles.com/mileage-plan-bonus.
If you have no Alaska status you may use the above link and see what happens.
Rocketmiles has gotten better at enforcing the ‘new member’ restriction but it still seems pretty widely defined.
Prices on Rocketmiles are usually higher (also depending on the offer used).
This is a sample search for the 4,000 points offer:
This is for the 3,000 miles offer:
Essentially you are paying $10-$20 for 5,000 Alaska miles. An excellent deal!