NEW CONSTRUCTION: Sewer line pump for property on an incline

[Kevin Polite]

There is a lot next to one I own that I'm going to build on that just came up for sale. There's a good and a bad. The good is that it has sewer capacity signoff from the County, something which is difficult to come by in that area. The bad is that it's the elevation is slightly lower and the most inexpensive way to connect to the sewer is to tap into what would be my the sewer on my adjacent property. The other routes to tie in would cost more than 2.5x more. The previous owner has both lots and had planned to put a manhole in the far corner to tie into what is now my property. 

How difficult is it or is it even advisable to try to use a sewer pump (if that's a thing). Also, what would happen in the case of electricity goes out? Would that mean they couldn't use the toilets during that time? 

Thought about a septic tank but that would take away too much of the property.

Anyone else been through this?