It's a nice list but I just think the Baroque/Pre-classical selection could use a little more beef. Within sub-full price per album category requirement, I think these albums can add a little variety to the meaning of Baroque:
http://www.amazon.com/Discover-Music...8100375&sr=1-3
Discover the Baroque Era - Various
Why: This is a great sampler of the Baroque for the money. Covers keyboard to voice, choral to sonata. Extremely cheap and very common. Gives a great idea of the variety and extravagance of the Baroque without having to spend money on multiple albums.
http://www.amazon.com/Bach-Organ-Wor.../dp/B0006ZFQMQ
Complete Organ Works by Bach - Karl Richter
Why: This set of album covers many Bach organ favorites including the famous Toccata and Fugue in D minor, the great Fantasia in G minor, the great Passacaglia, and others; the repertoire shown here sums up the genre of the Baroque organ category from Canon to Choralpartita. While the instrument may not be considered period (at least to the extent of my knowledge), Karl Richter's playing is very moderate without many spin offs or super improvisation, which makes it less disturbing for the newer individual who might be looking at this list.
http://www.amazon.com/Vivaldi-Strava...8100876&sr=1-1
La Stravaganza Concertos by Vivaldi - St Martin in the Fields
Why: The fast paced rhythm contrasted with the expressive slow movements can get people hooked onto the Italian orchestra, beyond the four seasons. Analogue-y orchestral texture of modern instruments with clear articulation into efforts of the Vivaldi insights make this set of dual discs a nice run for the money.
http://www.amazon.com/gp/product/cus...8101090&sr=8-4
Handel's Messiah - The English Concert, The English Choir
Why: This is one of the more moderately and consistently tempo'ed Messiah without losing any of it's grand. Orchestra-choir relation is clearly established with good acoustics and victorious soli passages without the rush (my preference, for example Paul McCreesh), or extra slow movements then extra fast movments (like Harnoncourt) . Least disturbing to the audience foreign to the Messiah apart from the Hallelujah.
http://www.amazon.com/Jean-Baptiste-...8101712&sr=1-2
collection of Lully orchestral - Le Concert de Nations
Why: The lack of French vocal not withstanding, Jordi Savall and the Le Concert de Nations in this album portrays the French Baroque with excellent dynamics, the heavy homophonic ouvertures and the joyous airs. Again like most of his albums, excellent acoustic with the right amount of sound from every instrument.
Of course I can add more albums but that would defeat the purpose of staying low priced and newbie friendly.