The old adage that you get what you pay for holds true here. First, searching the title is only one variable, the other is the examination of the instruments that are found. Unless you have extensive experience searching and examining titles in there county where the property lies I'd recommend you don't try to do it yourself.
I assume the attorney is offering to search and examine the title and issue you an attorney's opinion of title and the title company is offering to sell you a title report. If I'm correct, of the two I believe the attorney's opinion is better because the attorney and more importantly his E&O carrier, if he has one, would have liability for a covered loss you might suffer for relying on his opinion. The title report on the other hand, as I wrote earlier, probably has a nominal cap on liability for mistakes. I suspect that's why there's a difference in price. I may be mistaken and the title company is offering to issue a commitment for the $75 but you should confirm with both exactly what your getting for your money.
The reason I'm strongly recommending you get a title commitment is because if you bid on the property based on the attorney's opinion or a title report and win and later find out there's a encumbrance on the property which you weren't told about and was not extinguished by the Sheriff's sale then you can only look to recover your loss from the attorney or title company under the terms of the opinion or title report. If you get a title commitment and rely on it to buy the property you should be able to recover a covered loss from the title insurance underwriter. In addition, you'll want to be sure of what restrictions and easements will survive the sale and you would take title subject to.
I'm not an attorney and this is not intended to be legal advice, it's my opinion based on my years of handling title insurance claims across the country for various underwriters. I hope this helps.