Is this a bad deal

[Alicia England]

I'm currently under contract for 8 properties. 

6 of them are rented 

2 vacant 

seller is asking 810k for them all. This morning we found out the 2 vacant need a lot of work and he offered to drop the price to 105k total for the two of them or drop the overall package price to 800k and if that didnt work then we would just take the two vacant out of the package deal. We didn't discuss what the package price would be if we removed the two vacant properties. 

Heres my question is. The total cost of the portfolio ARV is 1.2M without the vacant properties. All 6 properties are rented, 2 are a year long lease while the other 4 are month to month

Here is a break-down of the rent

3bed 2bath 1,128sqft rented at $1,350/mo (current market rent is 1500-1700)

3bed 1bath 1,179sqft rented at $700/mo

(current market rent is 1200-1400)

3bed 2bath 920sqft rented at $1,000 

(current market rent 1200-1400)

3bed 1bath 1,170sqft rented at $550

(current market rent 1200-1400)

3bed 1bath 1,329 7338 Rented at $1,000/mo

(current market rent 1200-1400)

2bed  1bath 780sqft 1 Rented at $950/mo

(current market rent 1000-1100)

My question is would this be a good deal or should I try to get the price lower than $800k I told the seller if he'd separate the two vacant at 105k I'd help him sell them by assigning my interest in them but that I'd like to get the 6 rental properties still and offered 700k. He said to give him time to get back to his office and think it over. 

Currently we are under contract (on one contract although I asked if we could do them each on separate contracts)at 810k for all 8 properties. im worried that by paying 700k for the other 6 i would be in the negative instead of positive cash flow. This is my first time buying multiple properties and buying rentals.  Im just trying to be sure i dont get a bad investment. Thanks in advance for your help!