For me, UD works better than the ELF version. ELF isn't bad but if you have more detailed issues (oily lids and/or hooded lids) then my experience and those of my clients has been that UD works better between the 2.
There are also opportunities to purchase UD cheaper. Of course, it won't be $1 but it can be more affordable. For example, UD's website currently sells the Pro sized original primer for $20 (discounted from the original price). Also, right now you can purchase from Beauty.com during their Friends and Family sale for 20% off. If you are eligible for the UD Pro discount you can purchase for 40%. You can also get discount codes for $$$'s off on the UD website if you aren't eligible for the pro discount. Sephora will be having their VIB discount soon. Plenty of options out there for getting this cheaper if price is the only concern.