Is there anything else that distinguishes the early model 30+ from the later ones
Late models have the traveler on the cabin top on molded pylons, chamfers on the cockpit seat edges, propane locker under the stbd stern seat (I think) and lots of almond formica in the interior as opposed to wood veneer surfaces. From the photos posted so far it sure looks like a late model (mid-1984 and later). HIN will tell for sure. Original motor is 2 cylinder Universal Diesel 5416 like Franks model or Universal M18 like mine (depended on availability I guess) unless a different model was specified by the original purchaser or replaced at a later date.
In my opinion that's a very good price for an E30+ unless it needs lots of work.
I agree with Frank $8k does sound like a pretty good deal if it's in typical condition for its age with no major issues. BUT, all boats of this age that have not had continuous maintenance and upgrades will have lots of common problems, and possibly some major issues that may not be readily apparent from the survey. Sorting all these out will require diligence on your part if you wish to have a solid, reliable craft. As Christian mentioned, you can spend more for a boat that has been maintained well and probably come out ahead. For an older boat like this, spending 1x-3x the purchase price and a LOT of time getting it fixed up can be expected. The rule of threes applies: any project you contemplate will take 3x longer and cost 3x more than expected. On a sailboat everything is connected!
Have the surveyor pay special attention to thru hulls, hoses, prop shaft seal and other items that can sink the boat, and plan on replacing some or all of them anyway. Also have surveyor look carefully at the strut for looseness and galvanic corrosion, run a rag under the edges of the fuel tank to check for leaks and wiggle the motor to see how the engine mounts are. Access into the back of the boat is difficult through the lazarette, but modifications can be made to improve access from the quarterberth if needed.
Post up photos of any issues you and/or the surveyor finds and this group will be happy to give you opinions about how to fix it, or tell you to walk away and find another boat.
One final, biased, thought: Ericson boats are worth putting money into. They are well-designed, well-constructed boats that sail really well, and they don't look like a "Clorox bottle" as others here have so eloquently described some of the other brands of that era.