With a car, I would not stay right in either town---too much driving hassle. And, that budget may be challenge for you. If you can go higher, the Santa Caterina in Siena is perfect for you.

If we choose not to stay directly in either town, what would you suggest as alternatives. We generally like to stay in a town that has a good selection of restaurants for dinner each night. One where we can stroll after dinner and enjoy the town without feeling like it is deserted. We have stayed in Pienza before and liked it very much. It was easy to get into and out of each day for our daytrips. Would not want to stay anywhere smaller than that.

For Perugia, try Hotel Rosalba. It is at the bottom of the escalators and has "squeeze" parking. You'll fast learn how to get in and out of Perugia. Go to the Slow Travel website and look up tips.

I'll also recommend agriturismo Marciano near Siena, although for May, it is likely to stretch your budget and you will have a hike into Siena, and if you don't eat at the agriturismo restaurant, you will want a taxi back to your lodgings from the center of Siena.

If you dig deep on the internet with google looking for a b&b in Siena, you can stay within the walls and within in your budget, but you will need to park your car a long walk away. Might be worth it.

I too like to stay in smaller towns with good food options but a true Tuscan flavor. Other than Pienza, I have stayed in San Quirico, Montalcino, and Montepulciano and liked them all. The latter is larger at about 12,000 people. The Politian apartments are the best value in Tuscany, and Giacomo is a delight.

http://www.politian.com/

Siena with parking (check to make sure it's free):

Cannon D'Oro hotel also has a residence at the edge of town with bus service to the center.

http://www.cannondoro.com/residencesiena_i.htm

Hotel Chiusarelli is across the street from the historic center and has a small parking area.
http://www.chiusarelli.com/en-hotel-siena-tuscany/hotel.htm

Le Vigne has bus service to the center every 15 minutes (travel time 5 minutes or 15 minute walk).

http://www.poderelevigne.it/nuovo/pages_eng/index.html
http://www.bed-and-breakfast-in-italy.com/pagina.cfm?id=15182&idregione=16

Il Cadduccio says they are a 10 minute walk and has free parking.

http://www.ilcalduccio.it/index.php
http://www.bed-and-breakfast-in-italy.com/pagina.cfm?id=17005&idregione=16

Villa Fiorita is near the train station, but you can bus or take the new escalators up to the center. On street parking.
http://www.villafiorita-siena.com/en/

Perugia is more of a hassle driving in and out than Siena. I would pick another base and just visit Perugia for a day.

We found driving to Palazzo Ravizza in Siena very easy. You do have to go in/out a specific town gate (the hotel will email clear instructions), but once inside the city walls it's just a couple of turns to the hotel's parking lot. (You are allowed to drive to the hotel's front entrance to unload/load luggage.) The hotel is an easy walk to the Campo. Ask for a room on the back side of the hotel for a garden and countryside view. (This is what you see on the hotel's website.) Lots of exploring within an easy day's drive.

http://www.palazzoravizza.it/en

Thanks a bunch. I'll check on all the above.

We enjoyed our stay at the Palazzo Ravizza and did drive out from there for several day trips. I can't remember if we paid extra for parking but, if we did, it was worth it!

We did not pay for parking at P. Ravizza in October.

I can help you just for Perugia and suggest you Hotel Perusia www.hotelperusia.it, which is related to the center by shuttle or by feet in less than 10 minutes. You can see Assisi (just 30 minutes away by car) from its rooftop terrace. Bye