I have always heard that the two most important (and variable) components are the "transducers" and agree. Transducers are the components which change energy from mechanical to electrical or from electrical to mechanical. Those are the cartridge (mechanical of cartridge to electrical signal) and speakers, (electrical signals of system to mechanical movement of air.) I'm not so sure as to the impact of quality of a D-A converter. These seem to continually improve as newer models are incorporated. If you are into vinyl, no problem worrying about that one. I would get a decent record cleaner though. Really kills "POP's" The easiest transducers to audition are the speakers. Speakers have not only differing tonal balance, timbre and dynamics but also sound different in the room they are placed, so if possible try them in home with some ease of swapping them at the dealer for a different speaker. The efficiency of the speakers will dictate the required amplifier power and tolerance to the speaker's impedance tolerances needed to properly drive and to properly control the speakers. A low efficiency speaker on a high power amp may actually not be able to play as loud or be as dynamic as a high efficiency speaker on a low power amp. Same goes for rapid transient performance.
As such, speakers do have to be fitted with the appropriate electronic equipment. Back in the 1970's when I heard some speakers that just blew me away, I bought the drivers and crossover and built cabinets for them to save some $. At first, I used them with my older home built kit form electronics and an old low cost turntable and cartridge in an old KLH Model 20 system supplemented with a Heathkit 65 watt receiver. Since that time I have been improving my electronics including biampiing my speakers (Ya, the ones I bought in the 70's with a refoaming of the bass driver surrounds) and as a result continue to make some minor headway with the system but still am happy with the old speakers despite hearing some really expensive systems in fancy audio emporiums. Still use an old Audire stereo amp (got it used years ago) for the treble end. By all means go maximum $ for the speakers you like best and just continue upgrading the stuff feeding them. If you are on a fixed budget of $5000, I would not hesitate spending about up to $3500+ on the speakers alone. I have a lot of "used" electronics with an attitude I would rather spend the same money for an old good unit than a new not so good unit. Many dealers take trades. A lot of high end stuff gets boring to those with $ to burn and get traded for the latest and greatest. Such equipment may be on hand at a dealer and at a good price. I generally figure under 60% of "original new price" is a decent bargain. I look at it like getting a better piece of equipment for the same price as a lesser quality new piece, more than saving money.
As such, speakers do have to be fitted with the appropriate electronic equipment. Back in the 1970's when I heard some speakers that just blew me away, I bought the drivers and crossover and built cabinets for them to save some $. At first, I used them with my older home built kit form electronics and an old low cost turntable and cartridge in an old KLH Model 20 system supplemented with a Heathkit 65 watt receiver. Since that time I have been improving my electronics including biampiing my speakers (Ya, the ones I bought in the 70's with a refoaming of the bass driver surrounds) and as a result continue to make some minor headway with the system but still am happy with the old speakers despite hearing some really expensive systems in fancy audio emporiums. Still use an old Audire stereo amp (got it used years ago) for the treble end. By all means go maximum $ for the speakers you like best and just continue upgrading the stuff feeding them. If you are on a fixed budget of $5000, I would not hesitate spending about up to $3500+ on the speakers alone. I have a lot of "used" electronics with an attitude I would rather spend the same money for an old good unit than a new not so good unit. Many dealers take trades. A lot of high end stuff gets boring to those with $ to burn and get traded for the latest and greatest. Such equipment may be on hand at a dealer and at a good price. I generally figure under 60% of "original new price" is a decent bargain. I look at it like getting a better piece of equipment for the same price as a lesser quality new piece, more than saving money.