Is there a new word that means "philistine"?
Consider lowbrow:
adj.: Not interested in serious art, literature, ideas, etc. : relating to or intended for people who are not interested in serious art, literature, ideas, etc.
(M-W)
noun: A lowbrow person.
(Oxford Dictionary)
If a phrase works, something like "lowbrow materialist" could fit.
In light of your edit, consider;
bourgeois
: dominated or characterized by materialistic pursuits or concerns. Random House
: marked by a concern for material interests and respectability and a tendency toward mediocrity. M-W
Homo sap
Homo sap is short for Homo sapiens. As I am proposing it, it is a subspecies of Homo sapiens characterized by hyper-philistinism. The epitome of this subspecies can be found on TV shows of the Real Housewives, Lifestyles of the Rich and Famous, K up with the K genre.
Homo sapiens: "(Latin: “wise man”) human being [Credit: Encyclopædia Britannica, Inc.] the species to which all modern human beings belong. Homo sapiens is one of several species grouped into the genus Homo, but it is the only one that is not extinct." (http://www.britannica.com/topic/Homo-sapiens)
sap: "a foolish and gullible person." Merriam Webster (http://www.merriam-webster.com/dictionary/sap)
Sentence: "If homo sapiens goes extinct, it will be because of homo sap."
Any good thesaurus will provide a plethora of useful terms with senses similar in various ways to the dictionary sense of 'philistine' you cited. Try WordHippo for twenty nouns and six adjectives. Your dictionary appears to be working, so you can use it to attempt to fathom the various shades of meaning of those twenty nouns and six adjectives, and perhaps even puzzle out how those shades of meaning resemble, and differ from, the meaning of 'philistine'.
Of similar terms for the dictionary sense of 'philistine', 'yahoo' may be best:
- A name invented by Swift in Gulliver's Travels for an imaginary race of brutes having the form of men; hence transf. and allusively, a human being of a degraded or bestial type. (Cf. houyhnhnm n.) Freq. in mod. use, a person lacking cultivation or sensibility, a philistine; a lout, a hooligan.
["yahoo, n.". OED Online. September 2015. Oxford University Press. http://www.oed.com/view/Entry/231128?rskey=D6cHfM&result=1&isAdvanced=false (accessed November 24, 2015). Emphasis mine.]
A Google Ngram comparison of raw frequency data in the "English 1 Million (2009)" corpus suggests that the 'yahoos' have overrun the 'philistines' with a spike starting about 1990 that may be continuing today:
For your idiosyncratic sense of 'philistine' ("A person whose buying power exceeds his or her cultural and spiritual needs"), to my surprise, there is a new word (just what you asked for) that approaches that sense:
Babbitt, n.2 .... Etymology: < the name of George F. Babbitt, the eponymous protagonist of Sinclair Lewis's 1922 novel.
allusive (orig. and chiefly N. Amer.).A person likened to the character George Babbitt, esp. a materialistic, complacent businessman who conforms unthinkingly to the views and standards of his social set. Usu. in pl.
["Babbitt, n.2". OED Online. September 2015. Oxford University Press. http://www.oed.com/view/Entry/14196 (accessed November 23, 2015). Emphasis mine.]
Along with 'Babbitt' comes 'Babbitry' ("behaviour and attitudes characteristic of or associated with" Babbitt, noun, op. cit.), while 'philistine' must struggle along as best it can with 'Philistia' ("uneducated or unenlightened people collectively, philistines; the domain of such people; the community, culture, or lifestyle of philistines; philistinism", noun, op. cit.).
You don't seem to want a phrase, but I'll offer a couple anyhow.
More money than brains
seems to express your idiosyncratic sense of 'philistine', and
he buys his books by the pound
works when a long, drawn-out version of the same thought is desired. If even longer and more drawn-out suits the occasion,
... in matching colors
can be readily tagged onto the end of the pounding.