Hi,
I went and shot all seven of the North Carolina lighthouses this summer using the 645 FA 45-85/4.5 and the 645 FA 80-160/4.5 on six of them. For the seventh, I used 645 FA 200/4. That last really fell in between the 200/4 and 645 A* 300/4 so I went with the 200 and cropped it a little. All these on the 645D, which worked out wonderfully.
And, all were $300 each or less.
Edit1: Dug up from my old thread:
645 FA 45-85/4.5: $190.25
645 FA 80-160/4.5: $291.06
645 A* 300/4: $200.00
645 1.4x Converter A: $46.84
645 2x Converter A: $43.69
645 FA 200/4: $133.88
Edit2: The only item in the list that isn't all that good is the 2x TC on the 300/4 and I used it three times during all these coastal trips. Because a soft 2x TC is better than cropping with the 1.4x TC.
Edit3: Oh. And, I forgot. I also bought the 645 A 120mm macro lens for $149. Plus I have a 67 135 macro which I had picked up first and also a 67 Soft Focus. I haven't used the 67 135 since I got the 645 120.
Edit4: The old thread which has the lighthouse shots (plus what I have been doing with it all) within:
https://www.pentaxforums.com/forums/48-pentax-medium-format/405008-old-shooter-new-645d.html
Stan