Question about the different types of serial LCD's

i have few questions i've been searching everywhere in regards different serial lcd's.

1. have couple projects designed use "sparkfun" 3 wire serial lcd.  these seem way expensive are, $32 shipped, compared regular lcd's around $2.50 shipped.  there other lcd's compatible sparkfun ones cheaper, or can made cheaper?  did find 1 says uses uart, not sure if compatible or not, , still expensive, @ least $25 shipped, idea if work?  http://www.ebay.com/itm/serial-uart-sci-enabled-lcd-adapter-1602-lcd-disp-/120735812662?pt=lh_defaultdomain_0&hash=item1c1c6a4c36

2. serial lcd's, (either regular 4 wire, or sparkfun), solve issue of lcd artifacting, or still need manually workaround it?  mean is, when have used regular 16x2 non-serial lcd's on projects before, have variable on screen, lets number 15 example.  if 2 digit variable goes down 1 digit, 9 example, first digit not clear, though number 9, appear on screen 19, since 1 artifact.  way had found solve adding code monitor how many digits , clear first ones if necessary, work, nice if didn't have to.

3. there advantages 1 serial lcd on other, besides sparkfun 1 has 1 less wire?

thanks.

the product linked seems compatible arduino. may need modify minor things take code ran on sparkfun serial lcd run on one.

the serial lcd won't solve artifacts. following prescribed medicine cures ailment:

char buffer[17];
int number=9;
sprintf(buffer,"%2d",number);
lcd.print(buffer);

to 0 padding such 07 08 09, use "%02d".
refer cplusplus.com sprintf, fancy medicine cures all.

i biased towards serial lcd issue make , sell family of serial lcds , keypad panels myself take whatever consider fair argument:

3 vs. 4 wires:
some serial lcds lcds, i.e. output device. don't need read it. saves 1 line, rx on arduino. have both rx , tx possibly these reasons:
*update firmware require two-way communication verifying firmware @ upload.
*read lcd see what's on display, don't know why that's important. or read type of serial lcd ie. serial number or model number arduino knows there serial lcd connected.
*the serial lcd can connect other things. again, link product: this phi-panel has either integrated or optional 16-key keypad. user input on keypad processed transmitted arduino rx while commands control lcd or keypad (say enable/disable multi-tap) or messages display on lcd transmitted arduino lcd panel. requires two-way communications.

cost:
some serial lcds cheap because don't have processor on board. i2c serial interface, arduino can connect to. these i/o expanders give 8 additional i/o ports, enough run lcd. backpack has no intelligence. arduino spends resources , work , needs drive display special libraries provided makers. know of 2 sources besides ebay, adafruit, , our forum member fm. since there no processor on lcd backpack, solution cheap.

the more costly serial lcds have on-board processors controls display , in case of lcd backpack, possibly senses other inputs, process them, or run multi-tap input or other fancy stuff on on-board processor main arduino doesn't need worry those. more expensive , frees resources on arduino , more or less swappable other serial lcds on-board processors without ever needing special libraries. among few of sellers, sparkfun, moderndevice, 1 linked to, mine, etc. have same level of intelligence except mine, lowest cost functions. might explain why both sparkfun , moderndevice not interested in carrying serial lcd.

so logical conclusion buy phi-panel family of serial lcd lowest price (except fm's i2c backpack) , best functionality. rest of them in terms of functionality 5,000 lines of firmware code behind.

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