Without knowing your preferred dates for your mini-break it's hard to find out so I used 10th - 14th May (4 nights) as a rough guide, alot of places seem to have a limited number of rooms left so you'll need to book soon...
Falmouth Hotel - £396 Standard Inland Double
The Bay, Newquay - £320 Standard Double
Best Western Falmout Beach - £364 Double room
Copthorne Hotel Plymouth - £291.63 Double room/ £393.63 Superior Double
www.booking.com/searchresults.html?aid=320823;label=gb|cornwall-rg-1685|hotels-in-cornwall|;sid=5375 1c499e906ffda5fa5c360e65b94a;checkinmonthday=10;checkinyearmonth=2010-5;checkoutmonthday=14;chec koutyearmonth=2010-5;classinterval=1;region=1685;ssall=0;radius=1;hotelfacility=103
Carlton Court,Torquay - £300 Superior double (only 1 remaining!)
The Grand Hotel, Torquay - £376 - Standard Inland Double
Jurys Inn, Plymouth - £312 Standard Double
Haytor Hotel, Torquay - £316 Standard Double (only 5 available)
www.booking.com/searchresults.html?aid=320823;label=gb|devon-rg-1687|devon-hotels|;sid=53751c499e906 ffda5fa5c360e65b94a;checkinmonthday=10;checkinyearmonth=2010-5;checkoutmonthday=14;checkoutyear month=2010-5;classinterval=1;region=1687;ssall=0;hotelfacility=103
Hope this helps. Wish I was looking at hotels for me and DH...I need a holiday!!!